Dating twentieth century

The Centennial Exhibition of 1876 was held in Philadelphia, Pennsylvania to celebrate the 100th birthday of the United States.Although this grand world's fair showcased the United State's industrial accomplishments it also reminded Americans of their origins.

That is why such comparisons need to be deployed carefully. Dating as an institution is a relatively recent phenomenon which has mainly emerged in the last few centuries.From the standpoint of anthropology and sociology, dating is linked with other institutions such as marriage and the family which have also been changing rapidly and which have been subject to many forces, including advances in technology and medicine.Tree-ring dates from western Colorado show the construction of hogan-type dwellings in the 1100s A. that show Navajo-like characteristics and a Navajo homestead south of Gallup, New Mexico, has been dated to approximately 1380 A. In addition, a Navajo legend places the arrival of the Dinè, as the Navajo refer to themselves, in the vicinity of Chaco Canyon between roughly 9 A. Nevertheless when the Spanish arrived, the Navajo were already well ensconced on the Colorado Plateau and their numbers were growing.[2] The arrival of the Spanish produced a classic confrontation between denizens of the new and old worlds.